Well Safety Equipment

ABSTRACT

An independently operable disconnect device remotely disconnectable from an LMRP to reveal a riser profile compatible with a capping device connecter. A capping device including a capping device connector to be coupled to said riser profile. The capping device includes at least one blow-out preventer operable to stop the overflow of petroleum products from a well. Thus, a drilling marine riser may be fully disconnected from an LMRP in an emergency. Then the well may be subsequently capped.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application based on non-provisional applicationSer. No. 13/687,080 filed Nov. 28, 2012, hereby expressly incorporatedby reference herein.

BACKGROUND

This relates to drilling wells in deep water and particularly toequipment for improving the safety of workers on offshore drillingplatforms. As used herein, an offshore platform includes any device fordrilling in water.

Drilling in deep water can be a reasonably dangerous activity. Whensystems fail, workers can be exposed to the risk of fire and explosion.

In the Macondo disaster in the Gulf of Mexico, conventional systemsfailed. The workers on the platform were then tethered to the well andwhen the well exploded, many were injured and killed.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments are described with respect to the following figures:

FIG. 1 is a partial cross-sectional view of one embodiment of thepresent invention in place;

FIG. 2 is a partial depiction of the embodiment of FIG. 1 after welldisconnection according to one embodiment; and

FIG. 3 is a side elevation view of a well cap according to oneembodiment.

DETAILED DESCRIPTION

In accordance with some embodiments, a tool is provided to implement aseverable connection, between riser pipe and a well, for use inemergency situations. Particularly in cases like the Macondo welldisaster, where blow-out preventers and shear devices fail, it would bedesirable to enable the drilling platform to be separated from thewellhead for the safety of the workers. Otherwise, the workers areeffectively tied to the dangerous wellhead, under situations whenblow-out preventers and other safety devices have already failed.

In some embodiments, the severing system may be operated completelyindependently of those hydraulic and electrical systems responsible foroperating shear devices and blow-out preventers, which under thecircumstances contemplated here, may have failed. Then, because theconnection between the riser and the wellhead and the connection betweenthe mux lines and the wellhead may be severed, from a remote location,it is possible to separate the drilling platform from a wellhead. Thisdisconnection allows the drilling platform to move away from thewellhead, possibly reducing injuries and loss of life in some cases.

In FIG. 1, the lower portion of a riser 22 is shown in position on topof the independent riser disconnect device with the bottom of the deviceconnected to the Lower Marine Riser Package (LMRP) 10. Kill and chokeflexible lines 12 go from the top of the LMRP to the mini connectorsthat connect the kill and choke lines to the kill and choke lines on theSubsea blowout preventer (BOP) below. The device 20 (between riser joint22 and LMRP 10) is a controlled riser disconnect device that enables ariser to be severed from the wellhead in case of emergency when othercomponents, such as a blow-out preventer or LMRP, have failed allowingthe well to continue to flow. Once the connection has been released, insome embodiments, a free flow of petroleum products may result. Whilethis will create the potential environmental hazards, it would improvethe likelihood of survival for crew members on the offshore drillingplatform in some cases but also provide a male wellhead profile where aBOP or capping device can be installed to stem the flow of petroleumproducts.

Particularly, kill and choke line mini-connectors 14 connect the lowerportion of the kill and choke flexible lines 12 to the upper portion 16.The connectors 14 may be any kind of independently un-lockable connectorthat is synchronized to disconnect when main connector 18 disconnects.When the main connector 18 is disconnected, the mini-connectors unlockand disconnect at the same time as the main connector, allowing theupper and lower sections to disconnect together.

In some embodiments, the wellhead connector 18 may be an 18-¾″ wellheadconnector. The lower part or stub 24 of the device then is left in placeconnected to the LMRP 10 as shown in FIG. 2 and may be used by a cappingdevice (not shown in FIG. 1) to subsequently cap off the free flowingpetroleum products.

Thus, as shown in FIG. 2, a riser stub 24 extends upwardly to ribbedwellhead connector 25. A MUX cable quick disconnect 28 is left coupledto the line 13 and to control line 26 that goes to the drilling platform(not shown). Petroleum products may free flow as the result of theremoval of the disconnect device 20.

Then, referring to FIG. 3, the drilling platform may place a cappingdevice 30 on the wellhead attached to the stub 24. This may be doneusing drill pipe or a crane with a remotely operated vehicle (ROV)locking the capping device to profile 25 in one embodiment.

Thus in FIG. 3, a running tool 31 includes running tool connection 42 sothat the capping device 30 may be lowered from a ship on a drill string(not shown) to mate with and engage stub 24 (FIG. 2). In one embodiment,it hydraulically engages in seals on the stub 24 using the connector 38.Particularly, an 18-¾ inch connector 18 (FIG. 2) in one embodiment mayengage and hydraulically lock to an 18-¾ inch connector 38 (FIG. 3) onthe capping device 30.

A three cavity blow-out preventer including cavities 34 a, 34 b, and 34c controls the passage of petroleum product through the center bore ofthe capping device 30 that communicates with the passage within the stub24. The passage continues it's upwardly through the running tool 31. Aframe 32 surrounds a blow-out preventer 4. Each blow-out preventercavity includes an internal blind shear RAM 44 remotely controlled bybottle 36 in one embodiment. The hydraulic controls for the shear RAMSare entirely independent of any controls on the wellhead.

Thus, once the capping device 30 is sealed in place, the flow ofpetroleum product can be shut off by remotely operating the blind RAMs(not shown) within the blow-out preventers 34 to terminate the flow.

Thus, in some embodiments, the sequence is to first independently andremotely unlock the 18-¾″ wellhead connector 18. Then the flexible lines12 may be unlocked using the quick disconnect 14 including disconnectsfor kill and choke lines in some embodiments. Next, there may be anattempt to release the emergency disconnect 28 for the mux cables.Finally the device 20, which may be considered a lower marine riserpackage (LMRP), may be removed as shown in FIG. 2.

The overlying offshore platform picks up the capping device 30, that maybe contained within an onboard backup conventional lower marine riserpackage or LMRP connected to a redundant mux cable. Then the cappingdevice is run onto the drill pipe stub 24 and locked on to the openflowing top (using a remote operated vehicle or acoustic techniques), asshown in FIG. 3 in some embodiments. Finally the rig may move away fromthe wellhead 10 for the safety of workers.

Thereafter, the onboard LMRP may be used to drill a relief well. In oneembodiment, a new drilling operation may be conducted through thecapping device.

Thus in some embodiments it is possible to disconnect the riser abovethe blow-out preventer. While this may result in the free flow ofpetroleum products, it may preserve life and reduce injuries to workerson the platform. By using independently operated actuators, it ispossible to remove the device 20 even when other protection systems havefailed. This removal may be done using remotely operated vehicles,separate cables, an acoustic system or charged nitrogen bottles toactivate a relief connection.

References throughout this specification to “one embodiment” or “anembodiment” mean that a particular feature, structure, or characteristicdescribed in connection with the embodiment is included in at least oneimplementation encompassed within the present invention. Thus,appearances of the phrase “one embodiment” or “in an embodiment” are notnecessarily referring to the same embodiment. Furthermore, theparticular features, structures, or characteristics may be instituted inother suitable forms other than the particular embodiment illustratedand all such forms may be encompassed within the claims of the presentapplication.

While the present invention has been described with respect to a limitednumber of embodiments, those skilled in the art will appreciate numerousmodifications and variations therefrom. It is intended that the appendedclaims cover all such modifications and variations as fall within thetrue spirit and scope of this present invention.

What is claimed is:
 1. A method comprising: providing an independentlyoperable disconnect device that is remotely disconnectable from a lowermarine riser package (LMRP) to reveal a riser profile compatible with acapping device connector; providing a capping device with a cappingdevice connector to be coupled to said riser profile, said cappingdevice including at least one blow-out preventer operable to stop theoverflow of petroleum products from a well; and conducting a drillingoperation through said capping device.
 2. The method of claim 1including enabling a drilling rig to remotely physically disconnect theriser from an LMRP and Subsea blowout preventer combination.
 3. Themethod of claim 1 including enabling said disconnect device to bemounted on an LMRP over a blowout preventer.
 4. The method of claim 1including providing independent hydraulic controls for said cappingdevice.
 5. The method of claim 4 including providing a plurality ofremotely operated shear rams in said capping device.